1. Field of the Invention
This invention relates to a control system which by economically checking on a continuous basis at each beat of the loom that the dobby has effectively accomplished that for which it is programmed, ensures a weave free from any defect without the need for visually inspecting the formed fabric, and provides immediate and hence damage-free stoppage of the loom-dobby unit if any dobby components undergo breakage.
2. Description of the Related Art (Including information disclosed under 37 C.F.R. .sctn..sctn.1.97-1.99)
As is well known, a predetermined program is used to produce in dobbies a certain succession of movements which form a desired pattern by suitably operating the loom heddle frames.
In electronic rotary dobbies the reliability of the electronic circuit and the electromagnetic systems used is currently very high to the extent of practically guaranteeing the execution of the required operations. If however for any reason a dobby operation is performed incorrectly, which does indeed happen but only very rarely, this inevitably results in a defect in the produced fabric which may be difficult to identify on visual inspection by the operator.
Hence the current absence of any automatic control system in dobbies not only means that the constant costly presence of an operator is required, but in addition that reliable and immediate identification of the defect in the fabric cannot be achieved and hence that fabrics guaranteed free of defects cannot be obtained, and moreover immediate stoppage of the loom when mechanical breakages occur cannot be ensured, with the result that further serious damage can take place.
Automatic control systems have not been used up to the present time on looms both for constructional reasons in that dobbies have an axial pitch of 12 millimeters with up to twenty controls per dobby, and for reasons of cost and reliability.